Maybe in the EU - but ISIS fell off the bandwagon in the US years ago. I'd be curious to your claim, I've rarely run into ISIS in prod and I've had my hands on a lot of G2000 networks.

Cisco and Juniper are dinosaurs, the real disruption is being done by those smaller orgs not focused on pushing overpriced big-iron.

edit: I am a network engineer by trade, and have worked in large ISPs over the years.